The supposed Samsung Galaxy S3 June 21 release date has been a massive disappointment for Samsung enthusiasts in the U.S, who are facing significant delays and backlogs for pre-ordered phones.

AT&T, Verizon, T-Mobile and Sprint, which all have different release dates for the phone, have reported delays due to high demand. Most of the early birds who pre-ordered their phones promptly have received them, but many other customers who placed pre-orders at a later date are still waiting. And it seems those hoping to buy an S3 in a store will also encounter delays.

AT&T

In the company's support forum, some customers have reported receipt of their pre-ordered phone on June 21, but the company has since announced that supply constraints have resulted in some delays, which could mean some pre-orders could reach customers on June 25 or later.

AT&T still hasn't announced when the phone will hit stores, but after speaking to three New York stores, we were told the phone would hit shelves on June 28.

Sprint

A Sprint spokesperson has confirmed to Engadget that 16GB models of the pre-ordered phone were delivered on time on June 21, but a shortage in supplies means the 32GB pre-ordered model will be shipped next week. The carrier is unsure of when the phone will hit stores.

Some users who pre-ordered the 16GB through Sprint have told us that they have not yet received the 16GB model of the phone, despite Sprint's claim to have delivered them on time.

Pre-ordered mine on Sprint, and have not received ANY update whatsoever. Best Buy has no idea when they will come in, and Sprint has no information on it. My tracking number says nothing. This is really bad customer service, and it one strike against Sprint for me, Tim wrote in a comment on IBTimes.com

Verizon

The carrier's release date was originally set for July 10, but after receiving such high demand it has pushed back the launch by one day, now releasing on July 11.

T-Mobile

T-Mobile has not specified an in-store release date, but says it is also experiencing an order backlog. It has pushed back the release date of the phone to June 29 for markets outside major cities, including New York, Los Angeles, Houston and San Francisco. Otherwise the phone can be ordered through their Website.

The S3 heralds a 4.8-inch screen, Qualcomm S4 processor, voice control and face recognition. The new Super AMOLED display is 22 percent larger than its predecessor, bringing the phone into the Galaxy Note's phone/tablet hybrid category.

Samsung launched a face recognition feature on its latest phone in an effort to the make the smartphone experience more natural. The phone uses its front camera to identify the user's eye movement and ensures it never goes dark or switches off, while the user is looking at the phone.

Samsung has also improved its voice control feature with a sophisticated, Siri-like, voice recognition system dubbed S voice. The service allows users to make verbal demands to control their phone. Texts and emails can be dictated and photographs can be taken through voice commands using the feature.

The S3 also includes an NFC chip, which enables content sharing -- including video -- through tapping two phones together. The chip can also be used to make mobile payments.

The new Pop up Play feature on the phone enables multitasking, allowing users to open a video in a window on screen, and then use other apps with the rest of the screen.